Answer
Hertzsprung-Russell (HR) diagram is an essential tool used in stellar evolution. In the universe, there are several hundreds of billions of stars. Scientists use the tool, in differentiation, the billions of stars in the world from the sun. In the HR tool, there is plotting of the luminosity or energy output of a star, which is plotted on the X-axis of a graph against the absolute magnitude. The sun's magnitude is an absolute of +48, which, when plotted against its luminosity, helps in setting an apparent variance between the sun and any other star. Additionally, the sun has been identified as the primary star with a very high temperature. Hence the tool can locate the sun from other forms of stars. HR diagrams outline data such as temperature and luminosity or energy. However, star distance from the Erath is not a type of data represented in the charts.
Explanation:
Hope this helped you!
B. We can see only one side of the Moon from Earth.
( we only see one side of the moon because the moon rotates around the Earth)
A..........................................
Answer:
Alveoli
The bronchioles end in tiny air sacs called alveoli, where oxygen is transferred from the inhaled air to the blood.
Hope this helps :)
Speed is a description of how fast an object moves; velocity is how fast and in what direction it moves. In physics, velocity is speed in a given direction. When we say a car travels at 60 km/h, we are specifying its speed.